On the ozonolysis of unsaturated tosylhydrazones as a direct approach to diazocarbonyl compounds
作者:Younes Fegheh-Hassanpour、Faisal Ebrahim、Tanzeel Arif、Herman O. Sintim、Timothy D. W. Claridge、Nader T. Amin、David M. Hodgson
DOI:10.1039/c8ob00435h
日期:——
determined by NMR. This one-pot ozonolysis/Bamford–Stevens chemistry demonstrates both the tolerance of tosylhydrazones to ozone, and the subsequently added amine playing a dual role to directly transform the intermediate tosylhydrazone ozonides into products containing reactive diazo and ketone functionalities; such adducts are of particular value as precursors to cyclic carbonyl ylides for 1,3-dipolar cycloadditions
描述了使不饱和甲苯磺酰with与O 3然后与Et 3 N反应生成1,4-和1,5-重氮羰基体系的范围和限制。甲苯磺酰肼是由甲苯磺酰肼与容易获得的δ和ε不饱和的α-酮酸酯缩合而成的,在前一种情况下会生成2-吡唑啉,而在后一种情况下会生成α-重氮-ε-酮酸酯,尽管末端烯烃会生成四氢哒嗪醇。使用臭氧分解-Et 3 N策略,来自环烯酮的甲苯磺酰hydr可生成在1位带有醛或酯官能团的2,5-和2,6-重氮酮。α-重氮醛偏爱s-反式构象,旋转势垒为74 kJ mol -1在25°C下通过NMR测定。这种一锅的臭氧分解/ Bamford–Stevens化学方法证明了甲苯磺酰hydr对臭氧的耐受性,以及随后添加的胺起着双重作用,将中间体甲苯磺酰直接转化为含有反应性重氮和酮官能团的产物;这样的加合物作为1,3-偶极环加成的环状羰基酰化物的前体特别有价值。